Strain equalizing device



Oct. 11, 1932. w, p, FROST 1,881,459

STRAIN EQUALIZING DEVICE Filed Sept. 18, 1931 2 Sheets-Sheet 1 W. P.' FROST STRAIN EQUALIZING DEVICE OGt;

Filed Sept. 18, 1951 2 Sheets-Sheet 2 Patented Oct. 11, 1932 UNITED STATES PAT-En, caries WILLIAM P. FROST, OF JACKSON HEIGHTS, NEW YORK; ASSIGNOETO-EVANS ELEVATOR,

EQUALIZER COMPANY, OF BEDFURD, INDIANAQA GOEPOHATIONI OEINDIANAQ STRAIN EQUALIZING nnvicn Application filed. September 18,1931. Seriaiflo. 563,431.

My invention relates to a strain-equalizing device which in particular embodiment illustrated and herein described is arrai'iged to equalize the strain of the weight of an elevator car on the group of hoisting cables by which it is raised and lowered, butwhich is capable of application to other uses, such as distributing the applied stress of one element equally to several connected elements, as, for instance applying the power of a hand or foot brake lever equally to a. plurality of brake elements. The object of my invention is to produce a simple, strong and efi'icient device adapted for uses such as those indicated which shall be free from certain defects inherent in hydraulic: or pneumatic devices heretofore known and employed, and which shall be well adapted to serve the purpose for which it was designed. These ob jects I attain through a new organization of elements, employing a series of bellows elements which are severally connected to the hoisting cables, or other stress-sustaining parts and which are interconnected to equalize the stress among the connected parts, the essential elements of my invention being more particularly pointed out in the appended claims.

In the drawings, Figure 1 is a side v ew of an equalizing device and connected portions of the elevator car and hoisting cables of an elevator system;

Fig. 2 is an end view, and Fig. 3 a bottom view of the same;

Figs. 4 and 5 are horizontal sections in planes indicated by the dotted lines 4& and 55 of Fig. 1;

6 is a bottom view of the head-plate for the bellows element;

Fig. 7 is a transverse section of the same, in a plane indicated by the dotted line 77 of Fig. 6; and

Fig. 8 is a section of said head plate in an oblique plane indicated by the dotted. line 88 of Fig. 5.

Like reference characters indicate like parts in all the figures of the drawings.

Proceeding to a description of the construction illustrated, it will be understood that elevator cars, as generally constructed include frame members extending laterally. across the top of the car, fragmentary portions 1 of which are illustrated, and that the carends of the hoisting cables 2,0f which portions are shown, are engaged by a hoisting drum (not shown) at the top of the elevator shaft, which drum is rotated to raise and IOVV? er the car by any suitable power connections. The otherends of the cables are;in practice universally connected to a counterweight, and my novel equalizing devicesare equally well adapted to connect the counterweight to the counterweight ends of the cables. Because of the fact that the groove'softhe hoist-' ing drum sometimes varyslightl'y in diameter and the fact that the. cables may also vary slightly in size and the amount of'inherent stretch which they possess, the travel of'the cables may vary'somewhat, and iflthe cables are rigidly connected to the car the result is that the weight of the car will be unequallyborne by them. My device is designed to overcome thisdifliculty throughthe novel and desirable construction now to be described.

The frame members of the equalizing de viceinclude a head plate 3 which'by means ofv heavy corner bolts 4 and a pair of lower cross-plates 55 is clampedsecurely to the top frame members 1 of the car. The head plate is formed with cylindrical seats, in the present instance, six in number, correspondlnggto the number of hoisting cables, to receive the upper end of metal bellows members6,[such as the well-known sylphon bellows,,which are secured therein and make sealed connection therewith, as by means of a soldered joint. Above the bellows membereach seat is counter-bored partly through the plate and these counter-bores marked 7, are connectedby an oilcanal 8 which at one end terminates in a threaded opening 9 to the outside of the block, which is arranged to be closed by a suitable plug, to provide a means for filling the connected bellows members and passages with oil, or other suitable and equivalent liquid.

The lower end of each bellowsmember is supported by a sliding frame consisting of a lower plate 10, a pair of shackle rods 11-11,

and an upper plate 12 which is connected by a shackle bolt 13 and thimble socket 14 with the hoisting cables 2. The rods 14 slidingly engage guide orifices in the head plate 3.

Manifestly the oil in all the bellows must be under the same pressure, whatever the relative vertical position of the lower ends of the cables and connected lower ends of the bellows members and therefore must sustain the same portion of the total load, although the bellows members are individually free to expand and contract to accommodate a change of relative position, the oil flowing from one bellows to another to equalize the pressure. 7 1

Manifestly, also by suitable modification of the proportions and arrangement of associated parts, my invention may be adapted to equalize the application of an applied force (equivalent in effect to the force of gravity acting upon an elevator car, or other suspended load) in devices intended for other uses than in elevator systems so as to distribute the force equally to a plurality of stress-sustaining parts. I, therefore, do not desire my invention limited to the particular use above described, but desire to include all equivalents of the particular parts above described, and recited in the claims.

I claim: a

1. In an equalizing device for connecting a load and a plurality of series-sustaining parts, a head plate connected to said load, said head plate being formed with a liquid flow canal, a plurality of liquid-filled bellows members secured at one end to said head plate and communicating with said canal, and connecting members severally connecting the other end of said bellows and said stresssustaining parts.

2. In an equalizing device for connecting a load and a plurality of stress-sustaining parts, a head plate connected to said load, said head plate being formed with a liquid flow canal and a series of recessed bellows seats communicating with said canal, a plurality of liquid-filled bellows members severally making at one end sealed joints in said seats, and a plurality of sliding frames bearing severally on the other ends of said bellows and connected with said stress-sustaining parts;

a In testimony whereof, I have subscribed .my name.

7 WILLIAM P. FROST. 

